Both records (previous and existing one) cannot exist with each other because of the conflict.

Cause

Plesk Multi Server Bug #EXTPMS-1382.

Resolution

It is required to remove the record from the database directly on the service node and then re-run the sync. In the example below an assumption will be made that the initial record in the template was A record www.<domain> --><ip>, and new record is CNAME www.<domain> --> <domain>